In June, the weather in Keflavík is typically warm. Average daily high temperature in June is about 11 degrees above zero. On average, Keflavík has 18 rainy, 5 sunny, 5 cloudy, and 2 partly cloudy days in June. The rains are usually moderate. June as well as January, February, March, and April is considered the most uncomfortable time to visit Keflavík.